Wyniki wyszukiwania - BazTech

1

The activation energies and optimum temperatures of olive oil hydrolysis by lipase porcine pancreas

Miłek Justyna

Ecological Chemistry and Engineering. S

|

2021

|

Vol. 28, nr 3

389--398

EN

Lipase activity is a perfect indicator for the monitoring of processes of bioremediation of degraded soils. Lipase is also used in the processes of oil hydrolysis in wastewater treatment. To be able to predict and model processes with used lipase in environmental operations, knowledge of the kinetic parameters of the process are required. The paper presents the determined values of activation energies and optimum temperatures for porcine pancreas lipase. The parameters were estimated based on the literature of the activity curves vs. temperature for hydrolysis of olive oil by lipase. It was noticed that concentration of gum arabic added as an emulsifier during lipase activity measurements influences on the obtained values of determined parameters. A mathematical model describing the effect of temperature on porcine pancreas lipase activity was used. Based on the comparison analysis, the optimum temperature Topt were obtained in the range from 313.30 ±0.56 to 319.62 ±0.96 K, activation energies Ea were from 51 ±10 to 82.6 ±9.9 kJ/mol, and values of deactivation energies Ed were in the range from 122.7 ±4.0 to 150.9 ±5.8 kJ/mol.

2

The effect of pH on determination of activation energies and the optimum temperatures of hydrolysis of olive oil by lipase from porcine pancreas

Miłek Justyna

Acta of Bioengineering and Biomechanics

|

2021

|

Vol. 23, no. 3

25--31

EN

Purpose: The present paper reports the determination of the activation energies and the optimum temperatures of olive oil hydrolysis by porcine pancreas lipase with simultaneous effect of pH. Methods: The parameters were estimated based on the literature data on the activity curves versus temperature for olive oil hydrolysis by lipase obtained from porcine pancreas. It was assumed that both the hydrolysis reaction process and the deactivation process of lipase were first-order reactions by the enzyme concentration. A mathematical model describing the effect of temperature on porcine pancreas lipase activity was used. Results: The determinate activation energies Ea were from 31.37 ± 5.38 kJ/mol to 61.60 ± 11.46 kJ/mol, the optimum temperatures Topt were obtained in the range from 305.46 ± 1.26 K to 313.23 ± 1.18 K and the values of deactivation energies Ed were in the range from 65.18 ± 3.19 kJ/mol to 109.27 ± 6.79 kJ/mol. Conclusions: The obtained results (Ea, Ed, Topt) might find application in research on the prognosis of pancreatic cancer.

3

A numerical algorithm for obtaining an optimal temperature distribution in a 3D triple layered cylindrical skin structure

Zhang L., Dai W., Nassar R.

Computer Assisted Mechanics and Engineering Sciences

|

2007

|

Vol. 14, No. 1

107-125

EN

In recent years, there has been interest in research related to hyperthermia combined with radiation and cytotoxic drugs to enhance the killing of tumors. The objective is to control laser heating of the tumor so that the temperature of the normal tissue surrounding the tumor remains low enough so as not to cause damage to the tissue. To achieve this objective, it is important to obtain an optimal temperature field of the entire treatment region. In this paper, we develop a numerical algorithm for obtaining an optimal temperature distribution in a 3D triple layered cylindrical skin structure by pre-specifying the temperatures to be obtained at the center and perimeter of the treated region on the skin surface. The method is comprised of designing a laser irradiation pattern, solving a 3D Pennes' bioheat equation by a numerical scheme, and optimizing the laser power.